“At first blush, it definitely appears that this is a novel approach taken by the state of Nebraska and out of step with practices in other states,” ACLU of Nebraska Executive Director Danielle Conrad tells Nebraska Radio Network.

States have traditionally used a three-drug protocol for lethal injections, though some have moved to a one-drug protocol.

Nebraska state law requires the department to give the condemned inmate at least 60 days’ notice before the Attorney General requests an execution date from the Nebraska Supreme Court.

Sandoval received a death sentence after being convicted on five counts of first-degree murder for the deaths of five people in the Norfolk bank robbery in September of 2002. Prosecutors say Sandoval led a group of four men who attempted to rob the bank. He shot and killed three of the victims.

Nebraska held its last execution in 1997.

Conrad says the ACLU is reviewing the protocol and is consulting with capital punishment experts.

“And a lot of people are really scratching their heads over this very disappointing and strange approach,” according to Conrad.